Roller bearing cage and method for mounting a roller bearing cage

ABSTRACT

A rolling-element bearing cage includes a first side ring and a second side ring connected to the first side ring by a plurality of bridges defining a plurality of pockets configured to receive a rolling-element. The first side ring includes a joint at which the first side ring is configured to be opened to increase a diameter of the first side ring, and the first side ring and the second side ring and the plurality of bridges are made of steel and an outer diameter of the second side ring is greater than 500 mm.

Exemplary embodiments relate to a rolling-element bearing cage and amethod for installing a rolling-element bearing cage.

Rolling-element bearing cages are often used for guiding and spacingrolling elements in a rolling-element bearing. A variety of conventionalrolling-element bearing cages are known for this purpose. There areconventional rolling-element bearing cages that include two side ringsdisposed in the circumferential direction. These side rings can beconnected to each other via a variety of bridges. A pocket is formedbetween each two bridges and the side rings. A rolling element can bereceived in each pocket.

For installing in a rolling-element bearing, such rolling-elementbearing cages are usually first fitted with the rolling elements. Therolling-element bearing cage is often first mounted on an inner ring.Many inner rings include a flange. When the rolling-element bearing cagefitted with the rolling elements is then to be mounted on the inner ringincluding the flange, the rolling elements and the side ring must thenbe drawn or pushed over the flange. In many cases the flange has adiameter that is larger than a diameter on which the central axis of therolling elements are held in the rolling-element bearing cage. Thereforemany conventional bearing cages are expanded for mounting. For thispurpose the closed bearing cage is usually stretched in the radialdirection. After the mounting the side ring is contracted again or takenin again. Special tools are usually required for this purpose.

With cages having a large diameter the expanding and taking-in is notpossible or possible only with great difficulty. Large rolling-elementbearings can have, for example, an outer diameter over 500 mm or evenover 1000 mm. Therefore in many conventional large rolling-elementbearings, rolling-element bearing cages in a snap-in design are used.Here they can be, for example, so-called H-cages. However, themanufacture of such rolling-element bearing cages can be relativelycomplex. In addition, the assembly can also be complex or evendifficult. Reasons for this can be, for example, a large mass of thecage and the snap-in design.

There is therefore a need to provide a concept for improving theinstallation of a rolling-element bearing cage. A rolling-elementbearing cage as well as the method for installing the rolling-elementbearing cage according to the independent claims address this need.

According to one aspect, exemplary embodiments relate to arolling-element bearing cage that comprises a steel as material. Therolling-element bearing cage has at least one side ring. The side ringextends in a circumferential direction. In some exemplary embodiments afurther side ring can be present. Alternatively only a single ring thatlinks the pockets for receiving the rolling elements can also becentrally disposed. This can also be considered as a side ring. The atleast one side ring has an opening point. At the opening point the sidering can be opened. Thus a circumference of the side ring can beexpanded for an installation of he rolling-element bearing cage; inaddition the rolling-element bearing cage has an outer diameter that isgreater than 500 mm.

Since the side ring has an opening point, in some exemplary embodimentsan installing and a manufacturing of a rolling-element bearing fromsteel for a large rolling-element bearing can be simplified. Thereforethe rolling-element bearing cage can be drawn over a flange orinner-ring flange that has a larger diameter than the side ring in aclosed state. Thus in some exemplary embodiments the rolling elementscan be correctly positioned in the axial direction adjacent to theflange. In other words, the side ring or the rolling-element bearingcage can be drawn apart or separated at the opening point forinstallation. Therefore the opening point can optionally also beconfigured as a separating point. When the side ring is spread apart atthe separating point, in some exemplary embodiments a circumferentialdimension of the side ring or also of the rolling-element bearing cagecan enlarge. A distance between two separation surfaces of the openingpoint can then also enlarge. For this purpose in some exemplaryembodiments a circumference of the side ring need not necessarily changeuniformly. A shape of the side ring can change with a spreading apart atthe opening point. For example, the shape can change from a circularring to an oval or another shape. After a closing of the opening pointthe side ring or the rolling-element bearing cage can again assume itsoriginal shape.

In some exemplary embodiments the rolling-element bearing cage can havea diameter that is larger than 500 mm, 600 mm, 700 mm, 800 mm, 1000 mm,1100 mm, 1200 mm, 1300 mm, 1400 mm, 1500 mm, 1600 mm, 1700 mm, 1800 mm,2000 mm, 2100 mm, 2200 mm, 2400 mm, 2500 mm, 2700 mm, 2800 mm, 2900 mm,3000 mm.

In some further exemplary embodiments the opening point is exactly onesingle opening point. Thus in some exemplary embodiments it can be madepossible that the rolling-element bearing cage can fulfill its functionas an unsegmented rolling-element bearing cage. Nevertheless in someexemplary embodiments the rolling-element bearing cage can be installedbetter since it has the opening point. Even if the side ring has aplurality of opening points, these do not separate the rolling-elementbearing cage into a plurality of rolling-element bearing cage segments.Furthermore, the side ring can have a tilt- or hinge-region. The tilt-or hinge-region can lie opposite the opening point in the radialdirection. Thus in some exemplary embodiments it can be made possiblethat the side ring can be opened farther at the opening point. This canbe important, for example, if the side ring is comprised of a very stiffmaterial. The hinge- or tilt-region can optionally be configured suchthat it can be more easily deformed than other regions of the side ring.For this purpose the hinge- or tilt-region can comprise, for example, ahinge. Furthermore, the hinge- or tilt-region can also be configuredperforated. Additionally or alternatively the hinge- or tilt-region canhave a smaller diameter, a lesser thickness, or a lesser height thanother regions of the side ring. Additionally or alternatively the hinge-or tilt-region can be formed from a more elastic or softer material thanother regions of the side ring.

In an analogous manner to the first side ring the further or second sidering can also have an opening point. Thus in some exemplary embodimentsthe rolling-element bearing cage can be opened better for installation.The first and the second side ring can be connected to each other, forexample, via a plurality of bridges. Between each two bridges a rollingelement can possibly be received in a pocket. The pocket can be suitedfor receiving any type of rolling element. For example, the pockets canbe configured to receive a cylindrical roller, a spherical roller, atapered roller, or a ball. Thus according to some exemplary embodimentsthe rolling-element bearing cage can be used in a cylindrical rollerbearing (e.g., CRB), a spherical roller bearing (e.g., SRB), a ballbearing, or the like.

The opening points of the two side rings can be disposed flush to oneanother. In other words, the two opening points lie one-over-the-otherin the axial direction. Thus the opening points can be disposed at anidentical angular position of the two side rings or of therolling-element bearing cage. Since the opening points of the two siderings are disposed at the same angular position of the rolling-elementbearing cage, the two opening points can form a common opening point ofthe rolling-element bearing cage. Thus in some exemplary embodiments therolling-element bearing cage can be spread apart and opened at a singleopening point.

In some further exemplary embodiments the second side ring has a largerdiameter than the first side ring. Thus in some exemplary embodimentsthe rolling-element bearing cage can be suited for guiding the rollingelements in a tapered roller bearing. In some such exemplary embodimentsthe second side ring can be configured closed or without separating- oropening-point. Nevertheless the rolling-element bearing cage could thenbe mounted on the inner ring including the flange. This can be possible,for example, since the second side ring having the larger diameter canalso have a larger diameter than the flange of the inner ring. Althoughit is closed, the second side ring could thus be guided over the flangeof the inner ring. The first side ring with the smaller diameter canthen be separated at the opening point in order to overcome the flange.Of course the second side ring with the larger diameter can also have anopening point. Alternatively the side rings can each have a diameterthat is the same size. Rolling-element bearing cages according to theseexemplary embodiments can then possibly serve for guiding of rollingelements in cylindrical bearings.

In some further exemplary embodiments the rolling-element bearing cageincludes a closure element. The opening point can be closed or connectedby the closure element. Thus a circumference of the side ring can befixed after the mounting and the side ring or the rolling-elementbearing cage can be held on the inner ring after the mounting. Anunintended loosening of the rolling-element bearing cage from the innerring can then possibly be avoided. For example, the side ring cancomprise the closure element. Under certain circumstances each of theside rings can include its own closure element. Additionally oralternatively the closure element can be configured to simultaneouslyclose the opening points of the side rings. For example, the closureelement can be an adhesive-, weld-, solder-connection or the like.

The closure element can be configured releasable. Thus in some exemplaryembodiments the rolling-element bearing cage can be easily removedagain. In other words, the closure element could allow a non-destructivere-spreading or opening of the side ring on the opening side. Forexample, the closure element can be a screw-, rivet-, clip-,clamp-connection or the like.

In some further exemplary embodiments the opening point includes twoends. The ends overlap at least partially in the circumferentialdirection. This can be the case at least in a closed state of the sidering. Thus in some exemplary embodiments a sufficient surface forapplying the closure element can be provided. For example, each of theends can include a partial surface. In a closed state the two partialsurfaces can contact. In an opened or spread state a space or a gap canpossibly arise between the two partial surfaces. In some furtherexemplary embodiments the partial surfaces can also be configured suchthat in a closed state they have no contact to each other. The partialsurfaces can then optionally fixed to each other via the connectingelement.

Alternatively the partial surfaces can also bluntly abut on each other.This can possibly be the case in a closed state. In some exemplaryembodiments the opening points can thereby be very easily produced. Forexample, the opening points could then be incorporated in the side ringas a simple cut. In other words, the opening point can be configured asa gap.

In some further exemplary embodiments at least one of the side ringsincludes a plurality of cutouts. The cutouts serve to receive thebridges. A bridge or an end of a bridge can be inserted in each of thecutouts. Thus in some exemplary embodiments the rolling-element bearingcage can be built from two side rings that are connected via bridges.According to some exemplary embodiments these individual parts can bemanufactured in a simple manner. Since the side rings include thecutouts for receiving the bridges, in some exemplary embodiments a morestable rolling-element bearing cage can be provided. This could also besuited for large bearings. The plurality of the cutouts can be disposed,for example, on a radially outwardly directed circumferential surface ofthe side ring.

In some further exemplary embodiments the bridges are disposed bluntlybetween the side rings. The bridges here can be attached to a surface ofthe side ring. The surface can be directed, for example, in an axialdirection and facing the other side ring. Thus in some exemplaryembodiments an extension or an installation space of the rolling-elementbearing cage in a radial direction can be kept as small as possible.

A cross-section of the side ring can be L-shaped. Thus in some exemplaryembodiments the side ring can include a larger slip- or running-surfacefor the bridges. The side ring can be configured such that the bridgereceives an abutment surface in the axial direction on the side ring.Furthermore, the bridge can also receive an abutment surface in theradial direction on the side ring. Thus in some exemplary embodiments amore stable rolling-element bearing cage can be provided that is suitedfor guiding of rolling elements in large rolling-element bearings. Insome further exemplary embodiments the side ring can have anycross-section. For example, the cross-section can be configuredrectangular, square, quadrilateral, trapezoidal, polygonal, as acircular disc, as an annulus disc, or the like.

According to one aspect exemplary embodiments relate to a method. Arolling-element bearing cage can be installed with the method. For thispurpose a side ring of the rolling-element bearing cage is opened at anopening point. Subsequently the opened rolling-element bearing cage isinstalled into the rolling-element bearing. After the installing of therolling-element bearing cage in rolling-element bearing the side ring isclosed. Since the side ring is opened for installation, in someexemplary embodiments the side ring can be mounted on an inner ring witha flange. In some cases this could occur without an expensive tool. Toopen the side ring the partial surfaces can be spread apart or drawnapart at the opening point.

Further advantageous embodiments are described in more detail below withreference to exemplary embodiments depicted in the drawings, but are notlimited to said exemplary embodiments.

The Figures thus schematically show the following views.

FIG. 1 shows a schematic depiction of a perspective view of arolling-element bearing cage with rolling elements in an opened stateaccording to an exemplary embodiment on an inner ring;

FIG. 2 shows a schematic depiction of an enlarged section of FIG. 1;

FIG. 3 shows a schematic depiction of a cut side view of therolling-element bearing cage in an opened state on the inner ringaccording to FIG. 1;

FIG. 4 shows a schematic depiction of a plan view of the rolling-elementbearing cage in an opened state on the inner ring according to FIG. 1;

FIG. 5 shows a schematic depiction of a perspective view of therolling-element bearing cage according to FIG. 1 in a closed state;

FIG. 6 shows a schematic depiction of an enlarged section of FIG. 5;

FIG. 7 shows a schematic depiction of a perspective view of therolling-element bearing cage according to FIG. 5 in an opened state;

FIG. 8 shows a schematic depiction of an enlarged section of FIG. 7;

FIG. 9 shows a schematic depiction of a cut side view of therolling-element bearing cage with rolling elements according to FIG. 1in a closed state on the inner ring;

FIG. 10 shows a schematic depiction of an enlarged section of aperspective view of the rolling-element bearing cage from the front inan opened state according to an exemplary embodiment;

FIG. 11 shows a schematic depiction of a section of a perspective viewof the rolling-element bearing cage of FIG. 10 from behind;

FIG. 12 shows a schematic depiction of a section of a perspective viewof the rolling-element bearing cage of FIG. 10 in a closed state;

FIG. 13 shows a schematic depiction of an exploded view of therolling-element bearing cage according to an exemplary embodiment;

FIG. 14 shows a schematic depiction of a section of a cut side view of arolling-element bearing cage with rolling elements on an inner ringaccording to a further exemplary embodiment;

FIG. 15 shows a schematic depiction of a section of a perspective viewof the rolling-element bearing cage according to the exemplaryembodiment of FIG. 14;

FIG. 16 shows a schematic depiction of a section of a furtherperspective view of the rolling-element bearing cage according to theexemplary embodiment of FIGS. 14 and 15;

FIG. 17 shows a schematic depiction of a side view of a metal stripincluding a cutting gap for producing the bridge of the rolling-elementbearing cage according to an exemplary embodiment;

FIG. 18 shows a schematic depiction of a plan view of the metal stripaccording to FIG. 17;

FIG. 19 shows a schematic depiction of a perspective view of the metalstrip of FIGS. 17 and 18; and

FIG. 20 shows a schematic depiction of a side view of a side ring of arolling-element bearing cage according to a further exemplaryembodiment.

In the following description of the accompanying Figures, like referencenumbers refer to like or comparable components. Furthermore, summarizingreference numbers are used for components and objects that appearmultiple times in an exemplary embodiment or in an illustration, butthat are described together in terms of one or more common features.Components or objects that are described with the same or summarizingreference numbers can be embodied identically, but also optionallydifferently, in terms of individual, multiple, or all features, theirdimensions, for example, as long as the description does not explicitlyor implicitly indicate otherwise.

FIGS. 1 to 4 show different views of a rolling-element bearing cage withrolling elements in an opened state according to an exemplary embodimenton an inner ring of a rolling-element bearing.

As depicted in FIG. 1, a rolling-element bearing cage 1 comprises a sidering 2. The side ring 2 extends in a circumferential direction U. Theside ring 2 includes an opening point 3. The side ring 2 can be openedor separated at the opening point 3. A circumference of the side ring 2is expanded during an opening or separating of the opening point 3. Theside ring 2 is opened, for example for installation of therolling-element bearing cage 1. The rolling-element bearing cage 1 ismanufactured from steel and has a diameter that is greater than 500 mm.

The rolling-element bearing cage 1 comprises a second side ring 4. Thesecond side ring 4 also extends in circumferential direction U. Thefirst side ring 2 and the second side ring 4 are connected to each othervia a plurality of bridges 5. A pocket 6 is formed between each twobridges 5, the side ring 2 and the second side ring 4. The pocket 6serves for receiving a rolling element 7. In the exemplary embodiment ofFIGS. 1 to 4 a rolling element 7 is received in each pocket 6 of therolling-element bearing cage 1.

The rolling-element bearing cage 1 has a truncated cone as shape. Adiameter of the second side ring 4 is configured larger than a diameterof the first side ring 2. The rolling-element bearing cage 1 is thussuited for guiding of rolling elements 7 that are tapered rollers. Therolling-element bearing cage 1 could thus be used in a tapered rollerbearing.

In some further, not-depicted exemplary embodiments the rolling-elementbearing cage can include side rings with identical or essentiallyidentical diameters. In other words, the side rings can be the samesize. For example, in some exemplary embodiments the rolling-elementbearing cage can then be suited for the guiding of rolling elements thatare cylindrical rollers.

The second side ring 4 also includes an opening point 8. The openingpoints 3 and 8 of the two side rings 2 and 4 are respectively disposedbetween the two adjacent bridges 5-a and 5-b. The rolling-elementbearing cage 1 can thus be divided at a pocket 6-a. In other words, thetwo opening points 3 and 8 are located at the same angular position α.The angular position α is located here on an imaginary circle whosecenterpoint is the central axis M of the rolling-element bearing cage 1.This can be seen in the plan view of FIG. 4. A rolling element 7-a isreceived in the pocket 6-a. The rolling element 7-a is disposed on thesame side in circumferential direction U adjacent to the opening point 3or 8.

For installation in a rolling-element bearing the rolling-elementbearing cage 1 is disposed on an inner ring 9. This is shown in FIG. 2.The inner ring 9 includes a cylindrical inner bore 10. The inner ring 9and its bore 10 are oriented concentric to a central axis M of therolling-element bearing cage. The inner ring 9 includes a radiallyoutwardly directed circumferential surface 11. The inner ring 9 includesa conical raceway 12 on the circumferential surface 11. In an installedstate the rolling elements 7 roll on the raceway 12. Furthermore, theinner ring 9 includes a flange 13. The flange 13 represents a boundaryfor the rolling elements 7 in an axial direction M. The flange 13 islocated on an axial end of the inner ring 9. This end has a smallerdiameter than an opposing end in the axial direction. At the opposingend in the axial direction with a larger diameter the inner ring 9includes a flange 14. For installing the rolling-element bearing cage 1the rolling elements 7 are already received in the rolling-elementbearing cage 1 or the pockets 6. The rolling-element bearing cage 1 isopened for installation. For this purpose the side rings 2 and 4 areeach drawn apart at the opening points 3 and 8. It can thus be madepossible that the rolling-element bearing cage 1 and thus also therolling elements 7 can be drawn over the flange 13 of the inner ring 9.Here the rolling-element bearing cage 1 is slipped over the inner ring 9in a direction that extends from the flange 13 to the flange 15.

As can be seen in FIG. 3, there is a gap 17 between an edge 15 of theflange 13 facing the rolling elements 7 and a raceway 16 of the rollingelements 7. FIG. 3 shows a situation wherein the rolling-element bearingcage is not yet closed again at the opening points 3 and 8. In an openedstate of the side rings 2 and 4 it is possible that the raceways 16 ofthe rolling elements 7 lie at a larger diameter than a radiallyoutwardly oriented edge 15 of the flange 13. Thus in the exemplaryembodiment of the Figures the rolling-element bearing cage 1 can bemounted on the inner ring 9.

In some further, not-depicted exemplary embodiments only the first sidering may include the opening point. Since the second side ring has alarger diameter than the flange, the rolling-element bearing cage couldnonetheless be mounted on the inner ring.

After the positioning on the inner ring the rolling-element bearing cage1 is closed. For this purpose the side rings 2 are joined together againat their opening point 3. In an analogous manner the side rings 4 arealso joined together again at their opening point 8. This can occur, forexample, by a force with which the side rings 2 and 4 have been spreadbeing removed again. Additionally or alternatively the side rings 2 and4 can also be pressed together so that they close.

In some further, not-depicted exemplary embodiments an outer ring of therolling-element bearing can subsequently be mounted.

FIGS. 5 to 8 show different depictions of the rolling-element bearingcage 1 in closed and open states. For the sake of clarity the rollingelements and the inner ring are hidden.

FIG. 9 shows a schematic depiction of a cut side view of therolling-element bearing cage 1 with rolling elements 7 according to FIG.1 in a closed state on the inner ring 9.

By the joining together, closing, or sealing of the side rings 2 and 4the side rings 2 and 4 can each assume their original circumferenceagain. They need this for their function in the bearing. If the siderings 2 and 4 are each sealed at their opening points 3 and 8, thecircumference of the rolling-element bearing cage 1 shrinks. In theclosed state shown in FIG. 9 no more gap is present between the flange15 and the raceway 16 of the rolling elements 7. After the closing ofthe side rings 2 and 4 the rolling elements 7 abut with their raceways16 on the raceway 12 of the inner ring 9. The rolling elements 7 can nowbe held on an inner diameter that is smaller than an inner diameter ofthe flange 13 on which the edge 15 lies. Thus in some exemplaryembodiments it can optionally be prevented that the rolling elements 7and also the rolling-element bearing cage 1 can slide from the innerring 9 in the axial direction.

FIGS. 10 to 12 show different perspective views of the opening points 3and 8 of the rolling-element bearing cage 1. The opening points 3 and 8are configured in an essentially analogous manner. This can be seen inthe enlarged views of FIGS. 2, 6, 8, 10, 11, and 12. Therefore in thefollowing only the design of the opening point 3 is described withreference to FIG. 2.

At the opening point 3 the side ring 2 includes a first end 20 and asecond end 21. The ends 20 and 21 oppose each other in thecircumferential direction U. The first end 20 includes a bore 22. Thebore 22 serves for receiving a connecting element 19. The second end 21also includes a bore 23. The bore 23 also serves for receiving theconnecting element 19. In the exemplary embodiment of FIG. 2 theconnecting element 19 is a screw. The bore 22 and/or the bore 23 caninclude a thread as a counterstructure for the connecting element 19.Additionally or alternatively the connecting element 19 can alsointeract with a not-depicted nut.

The first end 20 and the second end 21 are configured such that they atleast partially overlap in circumferential direction U at least in aclosed state of the side ring 2. This is recognizable, for example, inthe detail view in FIG. 6. The first end 20 includes an overlap surface24. The overlap surface 24 is directed in an axial direction M of therolling-element bearing cage 1. The overlap surface 24 faces the sidering 4. The second end 21 correspondingly includes an overlap surface27. The overlap surface 27 is directed in an axial direction M of therolling-element bearing cage 1. The overlap surface 27 is located on aside of the end 21 facing away from the side ring 4. The overlapsurfaces 25 and 27 are configured such that in a closed state they cancontact at least sectionally. In some further exemplary embodiments theends can also be configured other than described. Beispielseise,contrary to the described exemplary embodiment the ends can overlap.

Furthermore, the first end 20 includes an abutment surface 25. Theabutment surface 25 is directed in a circumferential direction U. Theabutment surface 25 represents the element of the first end 20protruding farthest in the circumferential direction toward the secondend 21. The first end 20 includes a further abutment surface 26. Theabutment surface 26 is disposed set back in the circumferentialdirection U with respect to the second end 21. The abutment surface 26is located on an end of the overlap surface 24 opposing the abutmentsurface 25 in the circumferential direction U. The abutment surfaces 25and 26 both extend in an axial direction but protrude in opposingdirections from the overlap surface 24. The abutment surface 26 and theoverlap surface 24 can arise, for example, in a manufacturing of theopening point 3. For this purpose, for example, an essentially Z-shapedcut can be introduced in the side ring 2. Here the arms of the Z-shapedcut can have, for example, right angles with respect to one another. Thesecond end 21 correspondingly includes the described overlap surface 27.

Also with the second end 21 two abutment surfaces 28 and 29 protrudefrom the overlap surface. The abutment surface 28 is directed incircumferential direction U. It is located on an end of the overlapsurface 27 facing away from the first end 20 in circumferentialdirection U. In a closed state the abutment surface 28 can abut on theabutment surface 25. The abutment surface 29 is directed incircumferential direction U. The abutment surface 29 represents theelement of the second end 21 pointing farthest in the circumferentialdirection toward the second end 21. In a closed state of the side ring 2the abutment surface 29 can abut on the abutment surface 26. Theabutment surfaces 25 and 26 and 28 and 29 represent a radial stop of theopening point 3 or of a closing function of the side ring. Furthermore agroove 30 is introduced into the overlap surface 24. The groove 30extends in circumferential direction U. The overlap surface 27correspondingly includes a shoulder 31. The shoulder 31 also extends incircumferential direction U. The shoulder 31 is configured such that itcan be received in the groove 30. In other words, the ends 20 and 21 ofthe opening position 3 are interference-fit connecting elements. Thus insome exemplary embodiments a better positioning of the ends 20 and 21with respect to each other can be made possible. The ends 21 and 22 canbe screwed with the connecting element 19.

In further, not-depicted exemplary embodiments the ends can beconfigured in another manner For example, the ends can be configuredwithout groove or shoulder. Additionally or alternatively the overlapsurfaces or the partial surfaces can enclose an angle other than 90°.

In other, not depicted exemplary embodiments the ends can also beconnected using a blunt connection type, i.e., not overlapping. For thispurpose the two ends can be connected to each other in any manner. Forexample, the ends can be connected using a screw connection, a weldconnection, a solder connection, or the like. The screw connection canbe configured, for example, as a lockable or locked union nut, nut, orsleeve. In other words, a closure function is provided on the openingpoint or this includes a closure function.

FIG. 13 shows a schematic depiction of an exploded view of therolling-element bearing cage according to an exemplary embodiment.

As shown in FIG. 13 the side ring 2 includes a plurality of recesses 32.The side ring 4 correspondingly also includes a plurality of recesses33. The side ring 2 includes a radially outwardly directedcircumferential surface 34. The recesses 32 are introduced from thiscircumferential surface 34 in the side rings 2. The side ring 4 alsoincludes a radially outwardly directed circumferential surface 35. Therecesses 33 are introduced from the circumferential surface 35 in theside ring 4. A recess 32 of the first side ring 2 and a recess 33 of thesecond side ring 4 are respectively introduced at the same angularposition of the rolling-element bearing cage 1. The recesses 32 and 33respectively serve for receiving an end 36 or 37 of a bridge 5. Thus insome exemplary embodiments a better or more stable connection can bemade possible between the bridges 5 and the side rings 2 or 4. Therecesses 32 and 35 have a trapezoidal cross-section. In an analogousmanner the bridges 5 also have a trapezoidal cross-section.

In some further, not-depicted exemplary embodiments the plurality ofrecesses can also be formed on a radially inwardly directedcircumferential surface of the side ring.

In further, not-depicted exemplary embodiments the bridges can have anycross-section. The cross-section can, for example, be configured square,rectangular, quadrilateral, polygonal, triangular, round, as a circulardisc, as an annulus disc, or the like. For example, the bridges can bemanufactured from a solid material. The recesses can be configured suchthat they can receive the bridge. For example, the recesses can have across-section that corresponds to a shape of the bridge. In further,not-depicted exemplary embodiments the bridges can be attached to theside rings in another manner The side rings can then optionally have nocutout. For example, the bridges can be attached bluntly to the siderings. In some exemplary embodiments the side rings can be manufacturedcost-effectively without great effort. For example, the side rings canby manufactured by rolling of a flat material or as turned parts. Insome further, not depicted exemplary embodiments the side rings andbridges can also be formed one-piece. For example, the pockets can bepunched from a band.

FIGS. 14, 15, and 16 show different schematic depictions of arolling-element bearing cage according to a further exemplaryembodiment.

As depicted in FIG. 14 a rolling-element bearing cage 40 is disposed onan inner ring 9. The rolling-element bearing cage 40 is configured in anessentially analogous manner to the rolling-element bearing cage 1. Therolling-element bearing cage 40 includes a first side ring 41 and asecond side ring 42. The rolling-element bearing cage 40 differs fromthe rolling-element bearing cage 1 in the formation of the side rings 41and 42. The side rings 41 and 42 are configured in an essentiallyanalogous manner to the side rings 2 and 4. In contrast to the siderings 2 and 4 the side rings 41 and 42 each have an L-shapedcross-section. In other words the side ring 41 includes an abutmentsurface 43 as is recognizable in FIGS. 15 and 16. The abutment surface43 protrudes from the side ring 41. It extends to the side ring 42. Theabutment surface 43 thus extends from the side ring 41 out into thepocket 6. Furthermore, the abutment surface 43 has a smaller extensionin a radially outward direction than the side ring 41 or a main part 44of the side ring. Thus the abutment surface 43 forms an enlargedabutment surface for the bridges. Thus, for example, an improvedsupporting can be made possible for the bridges 5 by an L-extension onthe side ring.

For the sake of clarity some bridges are hidden in FIGS. 15 and 16. Inan analogous manner to the side rings 2 and 4 the side rings 41 and 42also have corresponding recesses 32 and 33 for receiving the bridges 5.

In some further, not-depicted exemplary embodiments the side rings withthe L-shaped cross-section can also be configured, for example, withoutthe recesses. The bridges can then be, for example, only so long thatthey can be introduced between the side rings. This length cancorrespond, for example, to a distance between a side surface 45 of theside ring 42 and a side surface 46 of the side ring 41. The sidesurfaces 45 and 46 here can each be directed in an axial direction M andfacing each other. The side surfaces 45 and 46 here can also formboundary surfaces for the pockets 6. Since the side rings 41 and 42 havean L-shaped cross-section, in some exemplary embodiments, for example, amore favorable axial abutment surface for the rolling elements orrollers can be provided.

FIGS. 17, 18, and 19 show different schematic depictions of a metalstrip with a cutting gap for producing the bridges of therolling-element bearing cage according to an exemplary embodiment.

The bridges 5 are produced from a metal strip 50 shown in FIG. 17. Forthis purpose the metal strip 50 can be cut, for example, with a water-,laser-jet or an erosion wire. With a longitudinal cut a bridge 5 can beseparated from the metal strip 50. In some exemplary embodiments onlyone cut is necessary for this purpose. This may be possible since at thesame time a roller-abutment surface, rotated by 180°, of the adjacentbridge 5 is also cut. In other words the bridges 5 can have a shape thatallows that the bridges 5 can be cut from the metal strip 50 withoutwaste material. In some exemplary embodiments the bridges 5 can therebybe cost-effectively manufactured with a water-jet-, laser-cut-, orerosion-method. A cutting gap 51 can be seen in FIG. 17. The cutting gap51 respectively separates two adjacent bridges 5.

In other words the rolling-element bearing cage 1 and also therolling-element bearing cage 40 comprise an upper and a lower side ring2, 4 or 41, 42. The bridges 5 or bridge segments are attached bluntly orin bridge-shaped cut-out recesses to these side rings, for example witha detachable or permanent connecting method. Examples of such methodsare welding, riveting, screwing, adhering, soldering, or the like. Thefeature of the rolling-element bearing cages 1 and 40 is the radiallyseparated side rings 2 and 4 or 41 and 42. In some exemplary embodimentsthese can be bent open for mounting of the rolling-element bearing cage1 or 40 over the flange 13 or inner-ring flange. Then the roller andcage assembly or rolling-element bearing cage 1 or 40 goes over theinner-ring flange 13. The side rings 2 and 4 or 41 and 42 cansubsequently be radially closed. In some exemplary embodiments the siderings 2, 4, or 41 and 42 can even produce a slight compensation of theradial clearance.

FIG. 20 shows a schematic depiction of a side view of a side ring of arolling-element bearing cage according to a further exemplaryembodiment.

FIG. 20 shows a side ring 52 with an opening point 58. The opening point58 separates a first end 54 from a second end 55. The ends 54 and 55 areopposingly disposed in the circumferential direction U and bluntly abuton each other. The side ring 52 further comprises a closure element 53.The closure element 53 is disposed such that it connects the end 54 andthe end 55 of the side ring 52 to each other in the circumferentialdirection. For this purpose an opening 57 is introduced in the side ring52 from a radially outwardly directed circumferential surface 56 of theside ring 52. From this opening 57 outward the closure element 53 can beinserted through the end 54 into the end 55. For example, for thispurpose the end 55 can also already include a bore. Conventional closuremechanisms can optionally also be fallen back on as closure element 53or closure mechanism. In some exemplary embodiments the closure element53 is configured to connect the side ring 52 to the opening point 58outward from a radially outwardly oriented circumferential surface 56.

In some exemplary embodiments the material- and manufacturing costs canbe significantly reduced by the design of the rolling-element bearingcage 1 or 40. Furthermore, in some exemplary embodiments expensivepressure tools or complex manufacturing methods can be omitted. In someof these conventional manufacturing methods blanks for steel-plate cagesfor large bearings are manufactured, for example, by flow forming.Pockets and a bore are subsequently introduced in a pot base bylaser-cutting. Laser-cutting is often used because in some conventionalsolutions a punching pocket-manufacturing is only possible up toapproximately 1100 mm. With a laser method, in some exemplaryembodiments metal plates with a thickness of up to 10 mm and an outerdiameter of up to 1300 mm can be treated or worked. Thus someconventional bearing cages are manufactured by machining (e.g.,milling). These manufacturing methods can be very time-consuming andpossibly require a five-axis milling machine. In other words, asteel-cage construction for bearings with an outer diameter of up to3000 mm or more can be provided with the rolling-element bearing cage 1or 40. In other exemplary embodiments the rolling-element bearing cage 1or 40 can also have other dimensions. With the rolling-element bearingcage 1 or 40 as steel-cage construction at least the side rings and thebridges can be manufactured from steel. The rolling-element bearing cagecan possibly be manufactured completely from steel.

Furthermore, in some exemplary embodiments complex installation methodscan be omitted. This can be the case above all compared to conventionalsolutions wherein a pattern inner ring with a decreasable flange ismanufactured in order to simulate snap-in installation with the pocketmanufacturing. Difficult-to-handle components or a difficult-to-handlepattern inner ring are often present in these conventional solutions.

With the rolling-element bearing cage according to some exemplaryembodiments, an installation and a manufacturing can be simplified, forexample, particularly with large bearings. Nevertheless, however, therolling-element bearing cage according to some exemplary embodiment cannot only be used for large bearings as described for the exemplaryembodiments. The rolling-element bearing cage according to someexemplary embodiments can be suited, for example, for any bearing sizeand bearing type. In some exemplary embodiments a side-ring shape,bridge shape, or side-ring- and bridge-design can be adapted accordingto the bearing type and a rolling-element shape. The embodiment of aradially opened cage can be useful, for example, in any cage-variant and-shape, in particular in the installation.

In other words, according to some exemplary embodiments therolling-element bearing cage includes a gap or is configured as a gapcage.

The exemplary embodiments and their individual features disclosed in theabove description, the following claims, and the accompanying Figurescan be meaningful and implemented both individually and in anycombination for the realization of an exemplary embodiment in itsvarious designs.

In some further exemplary embodiments, features that are disclosed inother exemplary embodiments as device features can also be implementedas method features. Furthermore, features that are implemented in someexemplary embodiments as method features can also optionally beimplemented in other exemplary embodiments as device features.

REFERENCE NUMBER LIST

1 Rolling-element bearing cage

2 First side ring

3 Opening point

4 Second side ring

5 Bridge

6 Pocket

7 Rolling element

8 Opening point

9 Inner ring

10 Inner bore

11 Circumferential surface

12 Raceway

13 Flange

14 Flange

15 Edge

16 Raceway

17 Gap

19 Closure element

20 First end

21 Second end

22 Bore

23 Bore

24 Overlapping surface

25 Abutment surface

26 Abutment surface

27 Overlapping surface

28 Abutment surface

29 Abutment surface

30 Groove

31 Shoulder

32 Recess

33 Recess

34 Circumferential surface

35 Circumferential surface

36 Bridge end

37 Bridge end

40 Rolling-element bearing cage

41 First side ring

42 Second side ring

43 Abutment surface

44 Main part

45 Side surface

46 Side surface

50 Metal strip

51 Cutting gap

52 Side ring

53 Closure element

54 End

55 End

56 Circumferential surface

57 Opening

58 Opening point

a Angular position

M Axial direction

U Circumferential direction

1. A rolling-element bearing cage having at least one first side ringextending in a circumferential direction, which includes an openingpoint at which the first side ring is configured to be opened to expanda circumference of the first side ring, wherein the rolling-elementbearing cage comprises steel and has an outer diameter greater than 500mm.
 2. The rolling-element bearing cage according to claim 1, comprisinga second side ring extending in the circumferential direction, whichincludes an opening point, at which the second side ring is configuredto be opened to expand a circumference of the second side ring.
 3. Therolling-element bearing cage according to claim 2, wherein the openingpoint of the first side ring and the opening point of the second sidering are axially disposed at a same angular positions of the side rings.4. The rolling-element bearing cage according to claim 2, wherein thesecond side ring has a larger diameter than the first side ring.
 5. Therolling-element bearing cage according to claim 1, further including aclosure element, configured to hold the opening first point closed sothat a circumference of the side ring is fixed.
 6. The rolling-elementbearing cage according to claim 5, wherein the connecting element isreleasable.
 7. The rolling-element bearing cage according to claim 1,wherein the first side ring includes opposing ends at the opening pointof the first side ring that at least partially overlap in thecircumferential direction.
 8. The rolling-element bearing cage accordingto claim 1, wherein the first side ring and/or the second side ringincludes a plurality of cutouts into which a plurality of bridges areinserted.
 9. The rolling-element bearing cage according to claim 2,wherein the first side ring has an L-shaped cross-section so that thefirst side ring includes an abutment surface on a side that faces thesecond side ring for the plurality of bridges.
 10. A method forinstalling a rolling-element bearing cage comprising: a) opening a sidering of the rolling-element bearing cage at an opening point; b)installing the rolling-element bearing cage with the opened side ringonto a rolling-element bearing; and c) closing and securing the openingpoint.
 11. The rolling-element bearing cage according to claim 3,further including a releasable closure element configured to hold theopening point in the first side ring closed, wherein the second sidering has a larger diameter than the first side ring, and wherein thefirst side ring includes partially overlapping opposing ends at theopening point of the first side ring.
 12. A method of installing therolling-element bearing cage according to claim 1 on a bearing innerring having a first diameter at a first end, the method comprising:opening the first side ring at the opening point of the first side ringsuch that a diameter of an opening in the first side ring becomesgreater than the first diameter; placing the first side ring over thefirst end of the bearing inner ring; and closing and securing theopening point.
 13. A rolling-element bearing cage comprising a firstside ring and a second side ring connected to the first side ring by aplurality of bridges defining a plurality of pockets configured toreceive a rolling-element, wherein the first side ring includes a jointat which the first side ring is configured to be opened to increase adiameter of the first side ring, and wherein the first side ring and thesecond side ring and the plurality of bridges comprise steel and whereinan outer diameter of the second side ring is greater than 500 mm. 14.The rolling-element bearing cage according to claim 13, wherein thesecond side ring includes a joint configured to be opened to increase adiameter of the second side ring.
 15. The rolling-element bearing cageaccording to claim 14, wherein the joint of the second side ring isaxially aligned with the joint of the first side ring.
 16. Therolling-element bearing cage according to claim 13, including means forsecurely closing the joint of the first side ring.
 17. Therolling-element bearing cage according to claim 13, including a pin forreleasably closing the joint of the first side ring.
 18. Therolling-element bearing cage according to claim 13 wherein the joint isformed by a first circumferential end portion of the first side ring anda second circumferential end portion of the first side ring and whereinthe first circumferential end portion overlaps the secondcircumferential end portion.